TPUG - Toronto PET Users Group/TPUG Users Group CD/TPUG Users Group CD.iso/CRS/crs52.d81/vdcram.seq

Text File | 2009-10-10 | 6KB | 100 lines

                          ╔NSTALLATION ╔NSTRUCTION
                          [╞OR ├-128 ╓IDEO ╒PGRADE]

    [1]  ┴LLOW AMPLE WORK AREA.  ╙PREAD OUT A TOWEL OR TWO TO AVOID
    SCRATCHING ├-128 CASE, AND HELP CATCH LOOSE SCREWS.

    [2] ┘OU WILL BE DEALING WITH EXTREMELY SENSITIVE ╔├'S.  ╨LEASE FOLLOW
    USUAL PRECAUTIONS TO AVOID STATIC CHARGES.

    [3]  ╘URN OVER COMPUTER (WITH FRONT FACING YOU), ╥EMOVE SIX (6) SCREWS,
    1 AT EACH BACK CORNER, 1 IN THE CENTER, AND 3 ACROSS FRONT. (╧LDER
    MODELS HAVE PHILLIPS-HEAD MACHINE SCREWS, HERE USE MEDIUM SIZE PHILLIPS
    SCREW DRIVER #1.) ╬EWER MODELS WILL HAVE HEX-SHAPED INSERT SCREWS.
    ╚ERE USE A 5/64 HEX KEY (ALAN WRENCH).  ╬OW TURN COMPUTER RIGHT SIDE
    UP.

    [4] ╘HE TOP AND BOTTOM HALVES OF THE COMPUTER ARE NOW HELD TOGETHER BY
    TWO INTERLOCKING PLASTIC TABS.  ╘HE TWO TABS PROTRUDING DOWN FROM THE
    TOP HAVE "TEETH" POINTING OUTWARD, THAT INTERLOCK WITH THE BOTTOM.
    ╘HESE TABS ARE LOCATED AT A POINT BETWEEN THE TOP ROW OF NUMBER KEYS
    AND THE SINGLE ROW OF FUNCTION KEYS AT BOTH SIDES OF THE KEYBOARD.
    ╨RESS THE TOP ╔╬ AT THIS SPOT, (AWAY FROM THE BASE AND TOWARDS CENTER),
    AS YOU LIFT THE TOP UP. ┘OU MAY ALSO TRY TO PULL THE BASE ╧╒╘ AT THE
    SAME POINT. ╧NCE ONE SIDE IS FREE, THE OTHER WILL FOLLOW EASILY.

    [5]  (A) ╬OTE ORIENTATION OF ╠╔╨ PART OF PILOT LIGHT ╠┼─ PLUG, ATTACHED
    TO LEFT SIDE OF CIRCUIT BOARD, (╔T POINTS OUT.)  ╨ULL APART MINI PLUG.

         (B)  ╘HE KEYBOARD IS ATTACHED TO THE CIRCUIT BOARD WITH A
    MULTI-WIRE MINI PLUG.  ╚ERE TOO, PULL APART PLUG, AND ╬╧╘┼ ORIENTATION.
    (╘HERE IS A BROWN WIRE CLOSER TO POWER SWITCH....BUT CHECK OUT UNIT
    BEING WORKED ON FOR VARIATION.)  ╫HEN SEPERATING THIS PLUG, NOTE THAT
    THE TWO PLASTIC PARTS MERGE COMPLETELY TOGETHER.  ╘HE "STILTS" COMING
    OUT OF THE CIRCUIT BOARD ARE ╬╧╘ WHAT IT IS PLUGED INTO.  ╘HEY ARE PART
    OF THE BOTTOM HALF OF THE PLUG.

         (C) ╥EMOVE THE HEAVY BRAID GROUND WIRE WHICH ALSO ATTACHES THE
    KEYBOARD TO THE CIRCUIT BOARD WITH A HEX KEY OR PHILLIPS HEAD.

    [6]  ╞REE THE ╥╞ SHIELD FROM THE BOARD.  ┴T LEFT REAR-CENTER IS A LARGE
    PHILLIPS HEAD SCREW.  ╥EMOVE IT.  ├OUNTING THIS SCREW, THE SHIELD IS
    ATTACHED TO THE BOARD BY 7 HEX SCREWS.  ╥EMOVE ALL 7.  ╚OLDING THE
    SHIELD TO THE BASE ARE ALSO TWISTED TABS, AT 4 PLACES ALONG THE FRONT,
    AND LEFT EDGE.  ╟┼╬╘╠┘ TURN TABS STRAIGHT WITH NEEDLE-NOSE PLIERS.
    ╫┴╘├╚ DIRECTION TABS ARE TWISTED, SOME GO ONE WAY, OTHERS THE OTHER.
    ╞INALLY, JUST ABOVE THE KEYBOARD MINI-PLUG ON THE RIGHT SIDE BY A TAB,
    THE ╥╞ SHIELD IS SOLDERED TO THE BOARD. ╒NSOLDER AT THIS POINT, AND
    THEN ╥╞ SHIELD CAN BE REMOVED.

    [7] ╧N THE MAIN BOARD IS A SMALL METAL BOX, AT LEFT-CENTER, ACTUALLY
    THE ONLY ONE THERE.  ╘HE TWO CHIPS TO BE REPLACED ARE LOCATED INSIDE.
    ╟ENTLY PULL UP AND REMOVE THE LID.  ╘HE CHIP LOCATIONS ARE MARKED ON
    THE CIRCUIT BOARD AS ╒23 AND ╒25.

    [8]  ╙EPERATE THE CIRCUIT BOARD FROM THE BOTTOM ╥╞ SHIELD, BY CAREFULLY
    TWISTING THE TABS HOLDING IT TO THE BOARD.  ╠EAVE THE BOTTOM ╥╞ SHIELD
    IN THE BOTTOM PLASTIC CASE, AND LIFT OUT THE CIRCUIT BOARD, WITH A
    "LEFT PULL AND UP" ANGLE, SO THAT PLUGS INSIDE PLASTIC BASE SLIP OUT
    BEFORE LIFTING UP.

    [9]  ╥EMOVE CHIPS ╒23 AND ╒25, BY EITHER A CLIP AND UNSOLDER OR SIMPLE
    UNSOLDER METHOD.  ╘HE OLD CHIP PINS MAY BE BENT ON THE BOTTOM, IF SO
    STRAIGHTEN BEFORE PULLING OUT. ┼╪┴═╔╬┼ CAREFULLY FOR DAMAGE!!  ╔F ANY
    SEE BELOW BEFORE PROCEEDING!! ╔NSERT ╔├ SOCKETS, BENDING BOTTOM PINS
    FOR A TIGHT FIT, AND SOLDER IN PLACE.  ╨LUG IN THE TWO #4464'S NOTING
    THAT THE "DIMPLE" ON THE #4464'S LINE UP WITH THE "DIMPLE" OUTLINE ON
    THE CIRCUIT BOARD.

    [10]  ╥EASSEMBLE CASING, CAREFULLY REVERSING EACH STEP.

    ╧OOOOPS!!
    ╘HERE ARE THREE COMMON GOOFS, WHICH SHOULD BE AVOIDED, BUT IF THEY
    OCCUR, HERE ARE THE PATCHES:

    [1]  ╙OLDER "RAN" AND NOW TWO PIN CONNECTIONS ARE CROSSED. ╧KEY, THIS
    IS EASY, JUST UNSOLDER THE CONNECTION, CAREFULLY SEEING THAT NO OTHER
    PIN CONNECTIONS ARE CROSSED.

    [2]  ╔N UNSOLDERING THE OLD CHIP, THE PIN CONNECTION GOT BURNED OUT.
    ╧KEY, THIS IS A BIT MORE TRICKY.  ┘OU HAVE TO EXAMINE THE CIRCUIT BOARD
    BOTH THE TOP AND BOTTOM SIDES, AND TRACE THE CONNECTION FROM THE BURNED
    OUT PIN HOLE TO WHERE IT GOES.  [╔F YOU HAVE A SCHEMATIC, BY ALL MEANS
    USE THIS.] ╘HEN, AFTER INSERTING THE ╔├ SOCKET, USE A "MAGIC MARKER" ON
    THE BOTTOM OF THE BOARD TO MARK THE BURNED OUT PIN, AND ITS CONNECTING
    POINT. ╥EMEMBER WHEN WORKING ON THE BOARD BOTTOM, ITS LOCATIONS ARE
    REVERSED, SO DOUBLE CHECK THAT YOU ARE TRACING CONNECTIONS CORRECTLY!!
    ╘AKE A LOOP OF LIGHT WEIGHT WIRE, ALLOW FOR A LOOP LONGER THAN THE
    DISTANCE TO BE CONNECTED, AND SOLDER THE WIRE TO THE TWO POINTS.  ╒SE
    ELECTRIC TAPE TO ISOLATE THE TWO SOLDER CONNECTIONS FROM ANY NEAR BY
    PINS, AT BOTH ENDS OF THE WIRE. ╘HEN FLATTEN THIS WIRE TO THE BOTTOM OF
    THE BOARD, GOING AROUND THE "PIN HILLS". ┴ND FINALLY TAKE SEVERAL LONG
    PIECES OF ELECTRICAL TAPE, MAYBE 4 OR 5 INCHES LONG, AND SECURE THE
    WIRE TO THE BOTTOM, SO THAT IT IS FLAT AGAINST THE BOARD.

    [3] ╔N REMOVING THE OLD CHIP, PART OF THE CIRCUIT BOARD TRACING TORE.
    ╫ELL, THIS IS PRETTY MUCH LIKE GOOF #2 ABOVE.  ═AKE SURE THAT THERE IS
    NO LOOSE TRACINGS TO CAUSE A SHORT.  ╘RACE OUT THE CONNECTION, GO TO
    THE BOTTOM OF THE BOARD, AND SOLDER IN A WIRE SPLICE CONNECTION AS
    DESCRIBED IN #2.